1. Field of the Invention
The present invention relates to a substrate processing apparatus used for carrying out a film-forming process for coating a substrate such as a semiconductor wafer with a resist solution or for applying a developing process to the substrate having an exposure treatment applied thereto.
2. Description of the Related Art
In the manufacturing process of, for example, a semiconductor device, a prescribed circuit pattern is formed on the surface of a semiconductor wafer by using a so-called xe2x80x9cphotolithography technologyxe2x80x9d. A series of processing in this photolithography process are carried out by using, for example, a resist coating and developing system such that a cleaned semiconductor wafer is coated with a photoresist solution so as to form a resist film, followed by exposing the resist film to light in a prescribed pattern and subsequently developing the exposed resist film.
A spin coating method is widely employed for the coating processing with a resist solution. In the spin coating method, a wafer is held on a spin chuck arranged within a coater cup, and a prescribed amount of a resist solution is dripped from above onto the central portion of the water while rotating the wafer together with the spin chuck. As a result, the dripped resist solution is centrifugally expanded toward the periphery of the wafer, thereby forming a resist film having a prescribed thickness.
If the temperature or humidity within the coater cup is changed in the spin coating method during the period between the dripping of the resist solution and the expansion of the dripped resist solution to form a film, the thickness of the formed resist film is changed. Therefore, in order to maintain constant the thickness of the resist film, the temperature and humidity within the coater cup are maintained constant by blowing an air whose temperature and humidity are controlled from above the coater cup into the coater cup.
In the manufacturing process of a semiconductor device in recent years, it is desirable to further decrease the thickness of the resist film formed on the semiconductor wafer. In this connection, it is required to blow an air having a uniform temperature distribution into the coater cup in order to form a thin resist film having a uniform thickness.
However, the conventional apparatus is defective in that the air blown into the coater cup is greatly nonuniform in the temperature distribution. Also, where the blowing rate of the air is changed, the nonuniformity of the temperature distribution is rendered more serious.
A first object of the present invention is to provide a substrate processing apparatus in which an air excellent in the uniformity of the temperature distribution is supplied into a substrate process section for processing the substrate.
Also, a second object of the present invention is to provide a substrate processing apparatus in which the uniformity in the temperature distribution of the blown air is maintained constant even in the case where the blowing rate of the air into the substrate process section is changed.
According to an aspect of the present invention, there is provided a substrate processing apparatus, comprising:
a substrate process section for applying a prescribed processing to a substrate; and
an air supply mechanism for supplying an air controlled at a prescribed temperature from above the substrate process section into the substrate process section;
wherein, said air supply mechanism comprises:
a tubular body having a substantially vertical wall and extending in a horizontal direction;
an air blowing device for blowing an air into said tubular body;
a first open portion formed in said vertical wall;
a first air introducing chamber arranged in a direction perpendicular to the longitudinal direction of the tubular body for taking in an air flowing within the tubular body through said first open portion and having a wall section facing said vertical wall;
a heater arranged within said first air introducing chamber for heating the air introduced into the first air introducing chamber;
a second open portion formed on the upper side in the central portion of the wall section of the first air introducing chamber;
a second air introducing chamber communicating with the first air introducing chamber via said second open portion and taking in the air heated by said heater through the second open portion;
a filter unit arranged below said second air introducing chamber for filtering the air introduced into the second air introducing chamber so as to supply a clean air into said substrate process section; and
an air stream control mechanism arranged between the second air introducing chamber and said filter unit for controlling the flow of the air from the second air introducing chamber into the filter unit.
According to the substrate processing apparatus of the present invention, it is possible to blow an air excellent in the uniformity of the temperature distribution into the substrate process section because used is an air supply mechanism in which the blowing state of the air is controlled at a plurality of points. As a result, the quality of the substrate can be enhanced, leading to an improved reliability of the manufactured semiconductor device. Also, the air blowing rate can be changed easily in accordance with various treatments applied to the substrate. For example, in the case of changing the air blowing rate from the first open portion into the first air introducing section, it is possible to prevent the uniformity of the temperature distribution of the air blown into the substrate process section from being decreased by changing the open area of the second open portion or by allowing the air stream control mechanism to change the air blowing rate.